Red Bull has launched a protest against rivals Mercedes over its use of its Dual Axis Steering (DAS) system during Friday practice at the Austrian Grand Prix.
Mercedes caught the attention of the F1 paddock in testing earlier this year when it first ran the system that allows the driver to change the alignment -- or toe angle -- of the front wheels while the car is on track. It is operated by moving the steering wheel back and forth, although Mercedes has not responded to speculation over how it impacts performance.
The system, which has already been outlawed in the 2021 regulations, was used by Mercedes in the opening practice sessions for this weekend's Austrian Grand Prix, reigniting the debate over its legality as Lewis Hamilton and Valtteri Bottas finished the day first and second. Following the second practice session Red Bull protested the system on the grounds that it breaches Article 3.8 of the technical regulations, which outlaws moveable aerodynamic devices, and Article 10.2.3, which prohibits changes to any suspension system while the car is in motion.
Speaking before the protest was lodged, Red Bull team principal Christian Horner said: "First of all, it is a very clever system, and so all credit to the ingenuity behind it. I think the fundamental question for us is, does it comply with the regulations?
"In what is, fundamentally, a grey area, obviously we do want clarity on it, as it does have an impact regarding the rest of this year. It's something outlawed for next year, so the question is, is it right for this year? They're the questions we'll be asking of the FIA through the necessary channels."
The grey area appears to centre on whether DAS is viewed as a steering system or a suspension device, although Red Bull has also protested its use as a movable aerodynamic device. The toe angle (the alignment of the front wheels, which DAS alters) is included as part of the suspension settings teams lodge with the FIA before leaving the pits for qualifying, and therefore a change to that could be perceived to be against regulations.
However, Mercedes will likely argue that DAS simply changes the angle of the wheels via the steering wheel, which is legal for obvious reasons. What's more, the fact the 2021 regulations had to be changed to outlaw DAS suggests the FIA believes it is legal under the 2020 rules.
Representatives from Red Bull and Mercedes were both been called to the stewards of the Austrian Grand Prix on Friday evening to make their case.
The specific advantages of DAS have not been named by Mercedes, but on Friday it appeared as though the drivers were using it on their warm-up laps before a fast lap. That suggests it is linked to the conditioning of the tyres, possibly by changing their alignment to control the temperature in the rubber.